OBJDUMP(1)

📦 version 2.47, in arch rolling

💅 OBJDUMP(1) 💅

okay bestie, this is the OBJDUMP(1) page from GNU Development Tools, and we are about to read object files like the main characters they are. ✨ Every flag, default, caveat, and tiny detail stays. No cap.

🌸 NAME 🌸

objdump — display information from object files

📜 SYNOPSIS 📜

objdump [-a|--archive-headers]
        [-b bfdname|--target=bfdname]
        [-C|--demangle[=style] ]
        [-d|--disassemble[=symbol]]
        [-D|--disassemble-all]
        [-z|--disassemble-zeroes]
        [-EB|-EL|--endian={big | little }]
        [-f|--file-headers]
        [-F|--file-offsets]
        [--file-start-context]
        [-g|--debugging]
        [-e|--debugging-tags]
        [-h|--section-headers|--headers]
        [-i|--info]
        [-j section|--section=section]
        [-l|--line-numbers]
        [-S|--source]
        [--source-comment[=text]]
        [-m machine|--architecture=machine]
        [-M options|--disassembler-options=options]
        [-p|--private-headers]
        [-P options|--private=options]
        [-r|--reloc]
        [-R|--dynamic-reloc]
        [-s|--full-contents]
        [-Z|--decompress]
        [-W|--dwarf]
        [-Wa|--dwarf=abbrev]
        [-WA|--dwarf=addr]
        [-Wr|--dwarf=aranges]
        [-Wc|--dwarf=cu_index]
        [-WL|--dwarf=decodedline]
        [-Wf|--dwarf=frames]
        [-WF|--dwarf=frames-interp]
        [-Wg|--dwarf=gdb_index]
        [-Wi|--dwarf=info]
        [-Wk|--dwarf=links]
        [-Wo|--dwarf=loc]
        [-Wm|--dwarf=macro]
        [-Wp|--dwarf=pubnames]
        [-Wt|--dwarf=pubtypes]
        [-WR|--dwarf=Ranges]
        [-Wl|--dwarf=rawline]
        [-Ws|--dwarf=str]
        [-WO|--dwarf=str-offsets]
        [-Wu|--dwarf=trace_abbrev]
        [-WT|--dwarf=trace_aranges]
        [-WU|--dwarf=trace_info]
        [-WK|--dwarf=follow-links]
        [-WN|--dwarf=no-follow-links]
        [-WD|--dwarf=use-debuginfod]
        [-WE|--dwarf=do-not-use-debuginfod]
        [--debug-dir=dir]
        [--map-global-vars]
        [-L|--process-links]
        [--ctf=section]
        [--sframe=section]
        [-G|--stabs]
        [-t|--syms]
        [-T|--dynamic-syms]
        [-x|--all-headers]
        [-w|--wide]
        [--start-address=address]
        [--stop-address=address]
        [--no-addresses]
        [--prefix-addresses]
        [--[no-]show-raw-insn]
        [--adjust-vma=offset]
        [--show-all-symbols]
        [--dwarf-depth=n]
        [--dwarf-start=n]
        [--ctf-parent=section]
        [--no-recurse-limit|--recurse-limit]
        [--special-syms]
        [--prefix=prefix]
        [--prefix-strip=level]
        [--insn-width=width]
        [--visualize-jumps[=color|=extended-color|=off]
        [--disassembler-color=[off|terminal|on|extended]
        [-U method] [--unicode=method]
        [-V|--version]
        [-H|--help]
        objfile...

🌈 DESCRIPTION 🌈

objdump displays information about one or more object files. The options control what particular information to display. This information is mostly useful to programmers who are working on the compilation tools, as opposed to programmers who just want their program to compile and work. 💖

objfile... are the object files to be examined. When you specify archives, objdump shows information on each of the member object files. Slay.

✨ OPTIONS ✨

The long and short forms of options, shown here as alternatives, are equivalent. At least one option from the list -a,-d,-D,-e,-f,-g,-G,-h,-H,-p,-P,-r,-R,-s,-S,-t,-T,-V,-x must be given.

-a, --archive-header — If any of the objfile files are archives, display the archive header information (in a format similar to ls -l). Besides the information you could list with ar tv, objdump -a shows the object file format of each archive member. 🎀
--adjust-vma=offset — When dumping information, first add offset to all the section addresses. This is useful if the section addresses do not correspond to the symbol table, which can happen when putting sections at particular addresses when using a format which can not represent section addresses, such as a.out.
-b bfdname, --target=bfdname — Specify that the object-code format for the object files is bfdname. This option may not be necessary; objdump can automatically recognize many formats.

For example,

objdump -b oasys -m vax -h fu.o

displays summary information from the section headers (-h) of fu.o, which is explicitly identified (-m) as a VAX object file in the format produced by Oasys compilers. You can list the formats available with the -i option.

-C, --demangle[=style] — Decode (demangle) low-level symbol names into user-level names. Besides removing any initial underscore prepended by the system, this makes C++ function names readable. Different compilers have different mangling styles. The optional demangling style argument can be used to choose an appropriate demangling style for your compiler. 💅
--recurse-limit, --no-recurse-limit, --recursion-limit, --no-recursion-limit — Enables or disables a limit on the amount of recursion performed whilst demangling strings. Since the name mangling formats allow for an infinite level of recursion it is possible to create strings whose decoding will exhaust the amount of stack space available on the host machine, triggering a memory fault. The limit tries to prevent this from happening by restricting recursion to 2048 levels of nesting.

The default is for this limit to be enabled, but disabling it may be necessary in order to demangle truly complicated names. Note however that if the recursion limit is disabled then stack exhaustion is possible and any bug reports about such an event will be rejected. 😭

-g, --debugging — Display debugging information. This attempts to parse STABS debugging format information stored in the file and print it out using a C like syntax. If no STABS debugging was found this option falls back on the -W option to print any DWARF information in the file.
-e, --debugging-tags — Like -g, but the information is generated in a format compatible with ctags tool.
-d, --disassemble, --disassemble=symbol — Display the assembler mnemonics for the machine instructions from the input file. This option only disassembles those sections which are expected to contain instructions. If the optional symbol argument is given (perhaps multiple times), then display the assembler mnemonics starting at (all the) symbol. If symbol is a function name then disassembly will stop at the end of the function, otherwise it will stop when the next symbol is encountered. If there are no matches for any symbol then nothing will be displayed. 🦋

Note if the --dwarf=follow-links option is enabled then any symbol tables in linked debug info files will be read in and used when disassembling.

-D, --disassemble-all — Like -d, but disassemble the contents of all non-empty non-bss sections, not just those expected to contain instructions. -j may be used to select specific sections.

This option also has a subtle effect on the disassembly of instructions in code sections. When option -d is in effect objdump will assume that any symbols present in a code section occur on the boundary between instructions and it will refuse to disassemble across such a boundary. When option -D is in effect however this assumption is suppressed. This means that it is possible for the output of -d and -D to differ if, for example, data is stored in code sections.

If the target is an ARM architecture this switch also has the effect of forcing the disassembler to decode pieces of data found in code sections as if they were instructions.

Note if the --dwarf=follow-links option is enabled then any symbol tables in linked debug info files will be read in and used when disassembling.

--no-addresses — When disassembling, don't print addresses on each line or for symbols and relocation offsets. In combination with --no-show-raw-insn this may be useful for comparing compiler output.
--prefix-addresses — When disassembling, print the complete address on each line. This is the older disassembly format.
-EB, -EL, --endian={big|little} — Specify the endianness of the object files. This only affects disassembly. This can be useful when disassembling a file format which does not describe endianness information, such as S-records.
-f, --file-headers — Display summary information from the overall header of each of the objfile files.
-F, --file-offsets — When disassembling sections, whenever a symbol is displayed, also display the file offset of the region of data that is about to be dumped. If zeroes are being skipped, then when disassembly resumes, tell the user how many zeroes were skipped and the file offset of the location from where the disassembly resumes. When dumping sections, display the file offset of the location from where the dump starts.
--file-start-context — Specify that when displaying interlisted source code/disassembly (assumes -S) from a file that has not yet been displayed, extend the context to the start of the file.
-h, --section-headers, --headers — Display summary information from the section headers of the object file.

File segments may be relocated to nonstandard addresses, for example by using the -Ttext, -Tdata, or -Tbss options to ld. However, some object file formats, such as a.out, do not store the starting address of the file segments. In those situations, although ld relocates the sections correctly, using objdump -h to list the file section headers cannot show the correct addresses. Instead, it shows the usual addresses, which are implicit for the target.

Note, in some cases it is possible for a section to have both the READONLY and the NOREAD attributes set. In such cases the NOREAD attribute takes precedence, but objdump will report both since the exact setting of the flag bits might be important.

-H, --help — Print a summary of the options to objdump and exit. 👑
-i, --info — Display a list showing all architectures and object formats available for specification with -b or -m.
-j name, --section=name — shows you all the info for the section called name. And bestie, you can stack this one — specify it as many times as your heart desires. 💅
--map-global-vars — spills the tea on your global variables. Ngl this one only works when the object file was compiled with the debug option — more precisely, it's living off DWARF2 debug information entries. It's lowkey iconic for tracking the location and type of every global variable in the given object file. ✨
-L, --process-links — displays the contents of the non-debug sections hanging out in separate debuginfo files that are linked to the main file. Heads up though: this option automatically implies -WK, and only the sections requested by your other command line options will actually be displayed. No bonus sections for free. 🎀
-l, --line-numbers — labels the display with the filename and source line numbers corresponding to the object code or relocs shown, using debugging information. Only useful with -d, -D, or -r, so don't come crying if you use it solo. 💖
-m machine, --architecture=machine — tells objdump which architecture to use when it's disassembling object files. This is the moment when you're dealing with object files that don't describe their own architecture info — think S-records — and you need to step in and be the main character. You can list all the available architectures with the -i option. 👑

For most architectures you can supply an architecture name and a machine name, separated by a colon. So like foo:bar would refer to the bar machine type in the foo architecture. This is helpful if objdump has been configured to support multiple architectures. 🦋

Now, if the target is an ARM architecture, this switch has an extra effect: it restricts the disassembly to only those instructions supported by the architecture specified by machine. And if you need to use this switch because the input file doesn't contain any architecture information, but you also want to disassemble all the instructions, use -marm. Periodt. 🌸

-M options, --disassembler-options=options — passes target specific information to the disassembler. Only supported on some targets, so vibe check your target first. If you need more than one disassembler option, you can either use multiple -M options or pile them together into a comma separated list. 🫶

🧚 ARC

For ARC, dsp controls the printing of DSP instructions. spfp selects the printing of FPX single precision FP instructions. dpfp selects the printing of FPX double precision FP instructions. quarkse_em selects the printing of special QuarkSE-EM instructions. fpuda selects the printing of double precision assist instructions. fpus selects the printing of FPU single precision FP instructions, while fpud selects the printing of FPU double precision FP instructions. On top of all that, you can choose to have all the immediates printed in hexadecimal using hex. By default, the short immediates are printed using the decimal representation, while the long immediate values are printed as hexadecimal. 💀

cpu=... lets you enforce a particular ISA when disassembling instructions, overriding the -m value or whatever is in the ELF file. This might be useful to select ARC EM or HS ISA, because the architecture is the same for those two and the disassembler relies on private ELF header data to decide if the code is for EM or HS. You might specify this option multiple times — only the latest value will be used, sorry to the earlier ones. Valid values are the same as for the assembler -mcpu=... option. ✨

🌈 ARM

If the target is an ARM architecture, this switch can select which register name set is used during disassembly.

-M reg-names-std (the default) selects the register names as used in ARM's instruction set documentation, but with register 13 called sp, register 14 called lr and register 15 called pc.
-M reg-names-apcs selects the name set used by the ARM Procedure Call Standard.
-M reg-names-raw just uses r followed by the register number.

There are also two variants on the APCS register naming scheme, enabled by -M reg-names-atpcs and -M reg-names-special-atpcs, which use the ARM/Thumb Procedure Call Standard naming conventions. (Either with the normal register names or the special register names, iykyk.) 🎀

This option can also be used for ARM architectures to force the disassembler to interpret all instructions as Thumb instructions by using the switch --disassembler-options=force-thumb. Genuinely useful when you're attempting to disassemble thumb code produced by other compilers. 🦋

💜 AArch64

For AArch64 targets this switch can be used to set whether instructions are disassembled as the most general instruction using the -M no-aliases option, or whether instruction notes should be generated as comments in the disassembly using -M notes. In addition, the -M annotate option can be used to customise the handling of undefined instructions when disassembling executables and shared libraries. Normally the disassembler will just show the hexadecimal value of the undefined instruction, but if annotation is enabled it will first try to find a symbol whose value matches the instruction's encoding. If there's a match, then the symbol name will be displayed instead. This is so useful when disassembling non-code sections which may contain function and data addresses. 🔥

⭐ x86

For the x86, some of the options duplicate functions of the -m switch, but they allow finer grained control:

"x86-64", "i386", "i8086" — select disassembly for the given architecture.
"intel", "att" — select between intel syntax mode and AT&T syntax mode.
"amd64", "intel64" — select between AMD64 ISA and Intel64 ISA.
"intel-mnemonic", "att-mnemonic" — select between intel mnemonic mode and AT&T mnemonic mode. Note: "intel-mnemonic" implies "intel" and "att-mnemonic" implies "att".
"addr64", "addr32", "addr16", "data32", "data16" — specify the default address size and operand size. These five options will be overridden if "x86-64", "i386" or "i8086" appear later in the option string.
"suffix" — when in AT&T mode and also for a limited set of instructions when in Intel mode, instructs the disassembler to print a mnemonic suffix even when the suffix could be inferred by the operands or, for certain instructions, the execution mode's defaults.
"annotate-immediates" — displays the symbol associated with immediate values, should there be one. Only works on executable binaries and shared libraries, not static object files. 🙈

🌸 PowerPC

For PowerPC, the -M argument raw selects disassembly of hardware insns rather than aliases. For example, you'll see "rlwinm" rather than "clrlwi", and "addi" rather than "li".

All of the -m arguments for gas that select a CPU are supported. These are: 403, 405, 440, 464, 476, 601, 603, 604, 620, 7400, 7410, 7450, 7455, 750cl, 821, 850, 860, a2, booke, booke32, cell, com, e200z2, e200z4, e300, e500, e500mc, e500mc64, e500x2, e5500, e6500, efs, power4, power5, power6, power7, power8, power9, power10, power11, ppc, ppc32, ppc64, ppc64bridge, ppcps, pwr, pwr2, pwr4, pwr5, pwr5x, pwr6, pwr7, pwr8, pwr9, pwr10, pwr11, pwrx, titan, vle, and future.

32 and 64 modify the default or a prior CPU selection, disabling and enabling 64-bit insns respectively. In addition, altivec, any, lsp, htm, vsx, spe and spe2 add capabilities to a previous or later CPU selection. any will disassemble any opcode known to binutils, but in cases where an opcode has two different meanings or different arguments, you may not see the disassembly you expect. And if you disassemble without giving a CPU selection, a default will be chosen from information gleaned by BFD from the object files headers — but the result, again, may not be as you expect. 😭

🦋 RISC-V

For RISC-V, the following options are supported:

"max" — disassemble without checking the architecture string. This is a best effort mode, so for overlapping ISA extensions the first match (possibly incorrect in a given context) will be used to decode the instruction. It's useful if the ELF file doesn't expose the ISA string, preventing automatic ISA subset deduction, and the default fallback ISA string ("rv64gc") doesn't cover all instructions in the binary.
"numeric" — print numeric register names, rather than ABI names (e.g., print "x2" instead of "sp").
"no-aliases" — disassemble only into canonical instructions. For example, compressed instructions will be represented as such ("addi sp,sp,-128" will be "c.addi16sp sp,-128").
"priv-spec=SPEC" — print the CSR according to the chosen privilege spec version (e.g., 1.10, 1.11, 1.12, 1.13).

🎀 MIPS

For MIPS, this option controls the printing of instruction mnemonic names and register names in disassembled instructions. Multiple selections from the following may be specified as a comma separated string, and invalid options are ignored (they simply don't get a rose 🌹):

"no-aliases" — print the 'raw' instruction mnemonic instead of some pseudo instruction mnemonic. I.e., print 'daddu' or 'or' instead of 'move', 'sll' instead of 'nop', etc.
"msa" — disassemble MSA instructions.
"virt" — disassemble the virtualization ASE instructions.
"xpa" — disassemble the eXtended Physical Address (XPA) ASE instructions.
"gpr-names=ABI" — print GPR (general-purpose register) names as appropriate for the specified ABI. By default, GPR names are selected according to the ABI of the binary being disassembled.
"fpr-names=ABI" — print FPR (floating-point register) names as appropriate for the specified ABI. By default, FPR numbers are printed rather than names.
"cp0-names=ARCH" — print CP0 (system control coprocessor; coprocessor 0) register names as appropriate for the CPU or architecture specified by ARCH. By default, CP0 register names are selected according to the architecture and CPU of the binary being disassembled.

Back to the -M options, bestie — this batch is all about register names and VAX entry masks, and it’s lowkey iconic 💅

"hwr-names=ARCH" — prints HWR names (hardware register, used by the rdhwr instruction) as appropriate for the CPU or architecture specified by ARCH. By default, HWR names are selected according to the architecture and CPU of the binary being disassembled. ✨
"reg-names=ABI" — prints GPR and FPR names as appropriate for the selected ABI. 🎀
"reg-names=ARCH" — prints CPU-specific register names (CP0 register and HWR names) as appropriate for the selected CPU or architecture. 🦋

For any of the options listed above, ABI or ARCH may be specified as numeric to have numbers printed rather than names, for the selected types of registers. You can list the available values of ABI and ARCH using the --help option. No cap, that --help menu is your bestie here 💖

For VAX, you can specify function entry addresses with -M entry:0xf00ba. You can use this multiple times to properly disassemble VAX binary files that don’t contain symbol tables (like ROM dumps). In these cases, the function entry mask would otherwise be decoded as VAX instructions, which would probably lead the rest of the function being wrongly disassembled. 😭

-p, --private-headers — prints information that is specific to the object file format. The exact information printed depends upon the object file format. For some object file formats, no additional information is printed. It’s giving “format-dependent surprise” 🙈
-P options, --private=options — prints information that is specific to the object file format. The argument options is a comma separated list that depends on the format (the lists of options is displayed with the help). For XCOFF, the available options are:
- "header"
- "aout"
- "sections"
- "syms"
- "relocs"
- "lineno,"
- "loader"
- "except"
- "typchk"
- "traceback"
- "toc"
- "ldinfo"

For PE, the available options are:

"header"
"sections"

Not all object formats support this option. In particular the ELF format does not use it. 🫶

-r, --reloc — prints the relocation entries of the file. If used with -d or -D, the relocations are printed interspersed with the disassembly. ✨
-R, --dynamic-reloc — prints the dynamic relocation entries of the file. This is only meaningful for dynamic objects, such as certain types of shared libraries. As for -r, if used with -d or -D, the relocations are printed interspersed with the disassembly.

Note: objdump does not support displaying RELR type relocations. These can be displayed by the readelf program. 💀

-s, --full-contents — displays the full contents of sections, often used in combination with -j to request specific sections. By default all non-empty non-bss sections are displayed. By default any compressed section will be displayed in its compressed form. In order to see the contents in a decompressed form add the -Z option to the command line. 🍓
-S, --source — displays source code intermixed with disassembly, if possible. Implies -d. 🌸
--show-all-symbols — when disassembling, show all the symbols that match a given address, not just the first one. Main character symbols only? No bestie, all of them 👑
--source-comment[=txt] — like the -S option, but all source code lines are displayed with a prefix of txt. Typically txt will be a comment string which can be used to distinguish the assembler code from the source code. If txt is not provided then a default string of "# " (hash followed by a space), will be used. 🎀
--prefix=prefix — specify prefix to add to the absolute paths when used with -S. 🦋
--prefix-strip=level — indicate how many initial directory names to strip off the hardwired absolute paths. It has no effect without --prefix=prefix. No prefix? No effect. Periodt 💅
--show-raw-insn — when disassembling instructions, print the instruction in hex as well as in symbolic form. This is the default except when --prefix-addresses is used. 🔥
--no-show-raw-insn — when disassembling instructions, do not print the instruction bytes. This is the default when --prefix-addresses is used. ✨
--insn-width=width — display width bytes on a single line when disassembling instructions. 🌈
--visualize-jumps[=color|=extended-color|=off] — visualize jumps that stay inside a function by drawing ASCII art between the start and target addresses. The optional =color argument adds color to the output using simple terminal colors. Alternatively the =extended-color argument will add color using 8bit colors, but these might not work on all terminals.

If it is necessary to disable the visualize-jumps option after it has previously been enabled then use visualize-jumps=off. 🫶

--disassembler-color=off, --disassembler-color=terminal, --disassembler-color=on|color|colour, --disassembler-color=extended|extended-color|extended-colour — enables or disables the use of colored syntax highlighting in disassembly output. The default behaviour is determined via a configure time option. Note, not all architectures support colored syntax highlighting, and depending upon the terminal used, colored output may not actually be legible. 😭

The on argument adds colors using simple terminal colors.

The terminal argument does the same, but only if the output device is a terminal.

The extended-color argument is similar to the on argument, but it uses 8-bit colors. These may not work on all terminals.

The off argument disables colored disassembly. 💅

-W[lLiaprmfFsoORtUuTgAckK], --dwarf[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links] — displays the contents of the DWARF debug sections in the file, if any are present. Compressed debug sections are automatically decompressed (temporarily) before they are displayed. If one or more of the optional letters or words follows the switch then only those type(s) of data will be dumped. The letters and words refer to the following information: 🌟
- a, =abbrev — displays the contents of the .debug_abbrev section. 🎀
- A, =addr — displays the contents of the .debug_addr section. ✨
- c, =cu_index — displays the contents of the .debug_cu_index and/or .debug_tu_index sections. 🦋
- f, =frames — display the raw contents of a .debug_frame section. 🌸
- F, =frames-interp — display the interpreted contents of a .debug_frame section. 💖
- g, =gdb_index — displays the contents of the .gdb_index and/or .debug_names sections. 👑
- i, =info — displays the contents of the .debug_info section. Note: the output from this option can also be restricted by the use of the --dwarf-depth and --dwarf-start options. 🫶
- k, =links — displays the contents of the .gnu_debuglink, .gnu_debugaltlink and .debug_sup sections, if any of them are present. Also displays any links to separate dwarf object files (dwo), if they are specified by the DW_AT_GNU_dwo_name or DW_AT_dwo_name attributes in the .debug_info section. 🔗
- K, =follow-links — display the contents of any selected debug sections that are found in linked, separate debug info file(s). This can result in multiple versions of the same debug section being displayed if it exists in more than one file.

In addition, when displaying DWARF attributes, if a form is found that references the separate debug info file, then the referenced contents will also be displayed.

Note — in some distributions this option is enabled by default. It can be disabled via the N debug option. The default can be chosen when configuring the binutils via the --enable-follow-debug-links=yes or --enable-follow-debug-links=no options. If these are not used then the default is to enable the following of debug links.

Note — if support for the debuginfod protocol was enabled when the binutils were built then this option will also include an attempt to contact any debuginfod servers mentioned in the DEBUGINFOD_URLS environment variable. This could take some time to resolve. This behaviour can be disabled via the =do-not-use-debuginfod debug option.

N, =no-follow-links — disables the following of links to separate debug info files. 🙈
D, =use-debuginfod — enables contacting debuginfod servers if there is a need to follow debug links. This is the default behaviour. 🌐
E, =do-not-use-debuginfod — disables contacting debuginfod servers when there is a need to follow debug links. 🚫
l, =rawline — displays the contents of the .debug_line section in a raw format. 📜
L, =decodedline — displays the interpreted contents of the .debug_line section. ✨
m, =macro — displays the contents of the .debug_macro and/or .debug_macinfo sections. 🍓
o, =loc — displays the contents of the .debug_loc and/or .debug_loclists sections. 📍
O, =str-offsets — displays the contents of the .debug_str_offsets section. 🎀
p, =pubnames — displays the contents of the .debug_pubnames and/or .debug_gnu_pubnames sections. 🌸
r, =aranges — displays the contents of the .debug_aranges section. 🌈
R, =Ranges — displays the contents of the .debug_ranges and/or .debug_rnglists sections. 🔥
s, =str — displays the contents of the .debug_str, .debug_line_str and/or .debug_str_offsets sections. 💖
t, =pubtype — displays the contents of the .debug_pubtypes and/or .debug_gnu_pubtypes sections. 👑
T, =trace_aranges — displays the contents of the .trace_aranges section. 🦋
u, =trace_abbrev — displays the contents of the .trace_abbrev section. 🎀
U, =trace_info — displays the contents of the .trace_info section. ✨

--dwarf-depth=n — caps how deep the .debug_info dump goes at n children, bestie. Only makes sense with --debug-dump=info. Default is "print every DIE, we're not afraid", and the special value 0 for n does the exact same thing. With a non-zero n, any DIE at or deeper than n levels just… doesn't get printed. And heads up: the range for n is zero-based.
--dwarf-start=n — only prints DIEs starting at the DIE numbered n. Again, only useful with --debug-dump=info. If you use it, it suppresses all the header info and every DIE before number n — so only the siblings and children of your chosen DIE show up. You can absolutely stack this with --dwarf-depth. ✨
--dwarf-check — turns on extra consistency checks for Dwarf info. Like a vibe check, but for debugging data. 💅
--debug-dir=dir — searches dir when it goes looking for separate debug info files.
--ctf[=section] — shows the contents of the CTF section you name. CTF sections are little matryoshka dolls of subsections and every one gets displayed, in order. Default section is .ctf, which is the name ld emits. 🎀
--ctf-parent=member — okay so if a CTF section has ambiguously-defined types, it's actually an archive of many CTF dictionaries, all inheriting from one dictionary that holds the unambiguous types. That member is named .ctf by default (same as the section holding it), but the name can be changed at link time with the "ctf_link_set_memb_name_changer" function. So when you're staring at CTF archives made by a linker that used the name changer to rename the parent archive member, --ctf-parent lets you say what that parent is called. iykyk 🫶
--ctf-parent-section=section — this one lets you pick a completely different section for the CTF parent dictionary (the unambiguous-type one) than the one used for the child dictionaries (the ambiguous remainder). The linker does not emit ELF objects structured like this — but some third-party linkers might. It's also convenient for inspecting CTF written out as multiple raw files so you can compose them with objcopy, which can put them in different ELF sections but not in different members of a single CTF dict. no cap.
--sframe[=section] — displays the contents of the SFrame section you specify. Default is the section named .sframe, the name ld emits. 🦋
-G, --stabs — displays the full contents of whatever sections you asked for. Specifically: the contents of the .stab, .stab.index and .stab.excl sections from an ELF file. Only actually useful on systems (like Solaris 2.0, hello ancient icon) where ".stab" debugging symbol-table entries live in an ELF section. On most other file formats those entries are interleaved with linkage symbols and you'll see them in the --syms output instead.
--start-address=address — starts displaying data at address. Affects the output of -d, -r and -s.
--stop-address=address — stops displaying data at address. Also affects -d, -r and -s. Bookend behavior, love that for you. 💖
-t, --syms — prints the symbol table entries of the file. Similar to what nm gives you, but the display format is different. The format depends on the file being dumped, and there are two main types. One looks like this:

        [  4](sec  3)(fl 0x00)(ty   0)(scl   3) (nx 1) 0x00000000 .bss
        [  6](sec  1)(fl 0x00)(ty   0)(scl   2) (nx 0) 0x00000000 fred

where the number in square brackets is the entry's number in the symbol table, the sec number is the section number, the fl value is the symbol's flag bits, the ty number is the symbol's type, the scl number is the symbol's storage class, and the nx value is how many auxiliary entries hang out with the symbol. The last two fields are the symbol's value and its name.

The other common format — usually what you see with ELF-based files — looks like this:

        00000000 l    d  .bss   00000000 .bss
        00000000 g       .text  00000000 fred

Here the first number is the symbol's value (sometimes called its address, iconic). The next field is actually a set of characters and spaces showing which flag bits are set on the symbol — described below. Next comes the section the symbol is associated with, or *ABS* if the section is absolute (i.e. not connected to any section), or *UND* if the section is referenced in the file being dumped but not defined there. After the section name comes another number: for common symbols that's the alignment, for other symbols it's the size. Finally the symbol's name shows up. periodt.

The flag characters break into 7 groups, bestie:

"l", "g", "u", "!" — the symbol is local (l), global (g), unique global (u), neither global nor local (a space), or both global and local (!). A symbol can be neither local nor global for a bunch of reasons (debugging use, for example) — but if it's ever both local and global that's probably a bug, ngl. Unique global symbols are a GNU extension to the standard ELF symbol bindings; for one of those, the dynamic linker makes sure that in the entire process there's exactly one symbol with that name and type in use. 💀
"w" — the symbol is weak (w) or strong (a space).
"C" — the symbol denotes a constructor (C) or is an ordinary symbol (a space).
"W" — the symbol is a warning (W) or a normal symbol (a space). A warning symbol's name is a message to display if the symbol following the warning symbol is ever referenced.
"I", "i" — the symbol is an indirect reference to another symbol (I), a function to be evaluated during reloc processing (i), or a normal symbol (a space).
"d", "D" — the symbol is a debugging symbol (d), a dynamic symbol (D), or a normal symbol (a space).
"F", "f", "O" — the symbol is the name of a function (F), a file (f), an object (O), or just a normal symbol (a space).

-T, --dynamic-syms — prints the dynamic symbol table entries of the file. Only meaningful for dynamic objects, like certain types of shared libraries. Similar to what nm gives you when you pass it the -D (--dynamic) option. The output format is like --syms, except an extra field gets inserted before the symbol's name giving the version info for the symbol. If that version is the default one used when resolving unversioned references to the symbol, it's displayed as-is; otherwise it goes in parentheses. 🙈
--special-syms — when displaying symbols, include the ones the target considers special in some way, the ones that normally wouldn't be interesting to you.
-U [d|i|l|e|x|h], --unicode=[default|invalid|locale|escape|hex|highlight] — controls how UTF-8 encoded multibyte characters show up in strings. The default (--unicode=default) gives them no special treatment at all. --unicode=locale displays the sequence in the current locale, which may or may not support them. --unicode=hex and --unicode=invalid display them as hex byte sequences enclosed by either angle brackets or curly braces. --unicode=escape displays them as escape sequences (\uxxxx), and --unicode=highlight displays them as escape sequences highlighted in red (if your output device supports it). The coloring is literally there to draw attention to unicode sequences where you might not expect them. 🔥
-V, --version — prints the version number of objdump and exits. slay.
-x, --all-headers — displays all available header information, including the symbol table and relocation entries. Using -x is equivalent to specifying all of -a -f -h -p -r -t. One flag, maximum main character energy. 👑
-w, --wide — formats some lines for output devices with more than 80 columns. Also stops truncating symbol names when they're displayed. your fave long symbol names stay intact 💅
-z, --disassemble-zeroes — normally the disassembly output skips blocks of zeroes. This option tells the disassembler to disassemble those blocks too, just like any other data. zeroes deserve screen time too 🫶
-Z, --decompress — the -Z option is meant to be used in conunction with the -s option (yes, that's exactly how the page spells it, we're keeping it fr fr). It tells objdump to decompress any compressed sections before displaying their contents.
@file — reads command-line options from file. The options read get inserted in place of the original @file option. If file doesn't exist or can't be read, the option is treated literally and not removed. Options inside file are separated by whitespace. A whitespace character can be included in an option by wrapping the whole option in single or double quotes. Any character (including a backslash) can be included by prefixing it with a backslash. And the file may itself contain more @file options — those get processed recursively. it's giving inception 🌀

🌈 SEE ALSO 🌈

nm(1), readelf(1), and the Info entries for binutils. go read them, bestie, they're the supporting cast and they ate 💖

🎀 COPYRIGHT 🎀

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".

and that's the whole page, babes 🦋 this lil masterpiece is from binutils-2.47, dated 2026-07-30 — OBJDUMP(1), signed, sealed, and absolutely iconic. now go disassemble something 💜✨

📦 where this page comes from

arch rolling: aarch64-linux-gnu-binutils 2.47-1 · GPL
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on 2026-11-04: a language model's rewrite of the original, under its terms